Oftentimes it is desired to mix flowing streams to produce desirable effects such as homogenization of the streams, thorough intermixing, establishment of uniform temperatures throughout the resulting stream and the like. Preferably, it is desirable to accomplish such mixing in a relatively static environment, that is, one in which there is a minimum of parts and most preferably no moving parts. Such mixers commonly have been referred to as static or motionless mixers and the mixing referred to as static mixing. Thus, while the physical interaction of the various streams which are to be mixed is produced, there are no physically moving structural elements or parts in the overall system which has obvious advantages.
The principle of static mixing by the use of helically-arranged passageways for use in in-line mixing of liquid streams is well known in the art as disclosed in the article, "Motionless Mixers" by Richard Devellian, AUTOMATION MAGAZINE, February 1972, pages 46 through 48. Other prior art which is typical of such mixing and mixers may be found by reference to U.S. Pat. Nos. 3,860,217 and 3,286,992. These static mixers, however, all basically have some sort of helical element or tubular channel which is fixed or secured to the interior of a tubular member or pipe, which has the obvious disadvantage of making the flow passageway very difficult to clean after the streams have been mixed. Also, the basic design parameters are fixed once the internal elements have been inserted or secured in place, thus making it very difficult and perhaps impossible to shorten or lengthen the mixing chamber after the design has been fixed.
Other prior art illustrative of this general area of technology includes U.S. Pat. No. 2,719,112, assigned to the assignee of the present invention, wherein a gas/solid contact system is disclosed. In this system the solid is normally within the vessel and to provide the desired contacting, a gas vortex flow is superimposed on the solid. Still further prior art patents include U.S. Pat. Nos. 3,261,593 and 3,391,908.